The case for the prosecution was based upon the presence of a strong motive for the crime, the quarrel between the husband and wife, the possession of arsenic (from the fly-papers) by the accused, the presence of arsenic in various foods and medicines alleged by witnesses to have been given to the deceased by his wife, and the discovery of arsenic in the body after death. In addition to this, evidence was given by the nurses that they had seen the prisoner manipulating the medicines, and by doctors and relations of Mr. Maybrick that he was not in the habit of taking arsenic. For the defence it was urged that death was due to acute gastritis, which was the result of a chill or improper food, and that arsenical poisoning was not the cause; that the fly-papers had been purchased by the prisoner for the preparation of a cosmetic for the face; and that the presence of traces of arsenic in the body was fully accounted for by the fact that Mr. Maybrick was an arsenic eater. Several medical men expressed opinions strongly opposed to the views of the prosecution, and it was pointed out by these that many of the symptoms characteristic of poisoning by arsenic had not been observed in this case. At the same time it was admitted that the effects produced by arsenic were often erratic, and, as Dr. Stevenson stated in his evidence for the prosecution, "There is no distinctive diagnostic symptom of arsenical poisoning. The diagnostic thing is finding the arsenic." The medical experts who gave evidence upon behalf of the prisoner were Dr. Tidy (who, like Dr. Stevenson, was an official analyst to the Home Office), Dr. Macnamara, and Professor Paul; and their view, which was strongly expressed, was that all the symptoms which had been described to them in the evidence pointed against arsenic having been the cause of death. The judge, in his summing up of the medical evidence, pointed out that expert witnesses were liable at times to take up the position of advocates with regard to scientific matters, and he warned the jury to take this into consideration in forming their conclusions. The analytical evidence as to the presence of arsenic in the body and in the food and medicine was given by Dr. Stevenson and by Mr. Davis. Davis had found no arsenic in the stomach, but it was discovered in the liver and intestines. In the bottle of the meat juice he had found half a grain in solution. Arsenic was present in the glass of the bottle, but to a less extent than in the glass of another bottle of the meat juice, in the contents of which no arsenic was present. Hence the glass could not have been the source of the arsenic found in the other bottle.